Turbos - How much do they lower the exhaust note?

[justinsstang]

It's a hard time trying to find turbo setups with different exhausts on these cars lol. I like the GT500 axle back, and MBRP axleback when paired with the O/R H pipe... but with the twin turbo setup, how much will it quiet it down?

Do I need to have a straight through muffler for it to not sound like a prius? Lol

My last car was a 06 with pacesetter LT, O/R H, and borla stinger with an M90 supercharger. It sounded good, but way too loud. I didn't really enjoy ever getting on the gas in town (and I live in town) because I felt like a total with my super loud exhaust LOL.

Just not wanting that to happen again, but I do appreciate a moderate, nice sounding exhaust. This green 2014 is an attention whore anyways. Can't stop at a gas station without someone telling me how they love the color, so I really don't need to be attracting any more of these folks while I'm stopping to grab a big gulp on my way to work.

So does anyone have any exhaust vids with twin turbo setups? I plan off road-H and some sort of catback probably. I'm thinking about doing my exhaust before turbos. Trying to find a medium between, not too loud and not too quiet hurts my brain and I'm tired. Hep. Hep meh.

 

[JeremyH]

Throw everything you know out the window. Once you see how the car sounds with a turbo, go from there/ Would be a waste of time and money to do it now imho. You don't need a fancy exhuast. Turbos like non chambered mufflers, cutouts and dumps.

A properly designed twin kit will not have a h or x pipe, forcing the exhuast to merge post turbine on a twin car creates turbulence and back pressure.

Twin kit, 3" exhuast, true dual (no forced merge) magnaflow magnapacks, turbo cams.





Twin kit, 2.5" resonator and muffler side exhuast, turbo cams.

 

[lethe]

I was running a on3 kit with mbrp axle backs and it was still plenty loud. The turbo changed the exhaust note more than it changed how loud it was.

 

[rford426]

I run 3" DP summit 3"glass pack with a dump just before axle....sorry it's a single turbo car doesn't take much to quiet a turbo car down though !

https://vimeo.com/112633059

 

[justinsstang]

Throw everything you know out the window. Once you see how the car sounds with a turbo, go from there/ Would be a waste of time and money to do it now imho. You don't need a fancy exhuast. Turbos like non chambered mufflers, cutouts and dumps.

A properly designed twin kit will not have a h or x pipe, forcing the exhuast to merge post turbine on a twin car creates turbulence and back pressure.

So you're saying it's best to never have the pipes meet on a turbo set up? No X, H, or prochamber, just straight pipes?

 

[weather man]

I am continually amazed how quiet my single dynomax dumped before the axle is.

 

[JeremyH]

So you're saying it's best to never have the pipes meet on a turbo set up? No X, H, or prochamber, just straight pipes?

Yes.

On a na car they are good to make some hp/tq for bank to bank pulse scavenging. On a Turbo car all the power and scavenging is done pre turbine and you want the post turbine exhaust gone as quickly as possible so any forced merges or splits, reductions, chambered mufflers etc create back pressure and can hurt power and rpm range.

 

[justinsstang]

Wow I'm glad you told me that lol. Was very close to buying an O/R H pipe.

Well damn now I don't know what to do =P I like a deep exhaust note and I dont know how I will accomplish that without either an H or some sort of chambered muffler.

Where can I get straight 3" pipes in place of my cats? I guess that's what I need, should be cheaper I would guess since there's no welding. Think ill just do straight 3" mid pipes, in to a full 3" catback with a straight through muffler. Would that be optimal?

Now I just gotta pick a catback. Is stainless works catback a bad choice for a turbo? Maybe a MBRP street series... Believe it's still a straight through muffler with more packing it than their race catback. Just don't want it super loud =P doubt the sound I want will be achieved with this setup though

 

[JeremyH]

Forget mid pipes man, everything you know about creating sound is different with a turbo setup.

Optimal would be dumps. But yes a shop can make the pipes go to your over axle pipes.

See what the car sounds like with the stock muffler. If you want more sound get a blow thru non chmabered style muffler like a dynamax or magnapack after the turbo setup is on.

In other words leave it alone for now. lol

 

[justinsstang]

Well I don't want to really just leave it, I wan't the cats gone before I start running turbos for sure, the rest I could leave I guess. I don't want to dump the exhaust and have it be super loud either =X

 

[JeremyH]

Speaking from experience, waste of money. I did long tubes and offroad pipe and did a lot of na pre turbo mods as well. If I could go back I would definetly go turbo first then take the mods from there.

That's the beauty of turbo's they muffle the exhaust enough to make dumps not ridiculously loud like an na or blown car.

Like mentioned, leave it all, get a turbo setup on and go from there. Thank me a later. Put that money your itching to spend towards a kit.

 

[justinsstang]

Where are you dumping them at?

And only thing I really care about leaving is the cats, don't want boost to tear one up and cost me a block =X

Only 2500 miles on the car though so they'd probably be fine for a while since they're stock cats. I don't have emissions where I live and really don't see a point in keeping em Did you keep your cats?

 

[JeremyH]

You can dump wherever you want. We do customization on our kits, here is a dump setup we did on our single kit.

Full exhaust with cutout and y pipe with dumps.

And then dump right on the down pipe after the wideband.

 

[eighty6gt]

I huffed a lot of fumes and got brain damage driving my '86 with dumps ahead of the axle. This isn't an issue anymore?

 

[JeremyH]

Everyone will have a preference, but I haven't had an issue, I don't run dumps on my car just cutouts. Newer cars are a lot better insulated and sealed that's for sure.

 

[justinsstang]

Can't wait until I get home from work so I can actually check out those vids lol. No signal at work and work computers block sounds & youtube both. FML, gonna be a long day haha.

So you have cutouts, meaning you have a flange in your exhaust that the exhaust actually comes out, rather than going through the full system.

Why even keep the exhaust if you're just going to have a cutout? Just seems like extra unnecessary weight unless you're talking electronic cutouts, to engage for normal driving/disengage for the track (or when you want make a camaro owner have to change their panties on the street).

Maybe I should do a 3" side exhaust after the turbo... Just use the cervini rear valance and have a custom 3" side exhaust made or something. HMMMMMMMM... Always wanted a side exhaust. Would save some weight no?

 

[RED09GT]

Did you keep your cats?

I haven't followed the turbo kits for the 11-14 cars but for the 05-09 cars almost all kits (except for 1 or 2) get rid of the stock cats. For a twin kit, if you really needed cats for whatever reason, I'd run a pair of 3 1/2" metallic spun cats to get as big of a cross section as possible to reduce the restriction.
I have the quiet version of the magnaflow cat back with a powerhouse single turbo setup and it is barely louder than it was with the stock h-pipe and cats. It comes alive a bit at WOT but it is really quiet.

 

[JeremyH]

Can't wait until I get home from work so I can actually check out those vids lol. No signal at work and work computers block sounds & youtube both. FML, gonna be a long day haha.

So you have cutouts, meaning you have a flange in your exhaust that the exhaust actually comes out, rather than going through the full system.

Why even keep the exhaust if you're just going to have a cutout? Just seems like extra unnecessary weight unless you're talking electronic cutouts, to engage for normal driving/disengage for the track (or when you want make a camaro owner have to change their panties on the street).

Maybe I should do a 3" side exhaust after the turbo... Just use the cervini rear valance and have a custom 3" side exhaust made or something. HMMMMMMMM... Always wanted a side exhaust. Would save some weight no?

Electric cutouts don't holdup and fail under the pressure and temps turbo's see. The butterfly valve much like a throttle plate doesn't hold up. And they are expensive to boot.

We run 3 bolt cutouts with a cover plate held on by 3 wing nuts. It can easily be removed or capped in minutes depending on your mood. I currently have mine capped all the time as I have a really free flowing exhaust and only intend to open them at the track. Bobby runs his open all the time and, he does have a side exhaust and its really restrictive its 2.5" piping going through a resonator and muffler on each side with a couple 90 degree bends. He picked up 46rwhp and 48rwtq removing the cutout caps with his side exhaust.

We run it this way for that exact reason. Some guys want dumps, and remove their exhaust some guys want to run it all through the stock exhaust and to sound stock and some want the option for both. This is the easiest way to provide best of both worlds for the average guy.

 

[justinsstang]

The sad part is I probably will end up not caring too much about exhaust when I have whooooooosh and PSHHHH turbo and blow off valves noises lol

3 more hours until I get home and see what those vids are about

 

[JeremyH]

LOL.